I usually use sys.exit() to stop a script from running if some error condition is met. So for example, if a user put in a wrong input variable...import sys
var =gp.GetParameterAsText(0)
if var not in ("cat","dog","mouse"):
print "ERROR: You entered the wrong animal! Exiting script..."; sys.exit()
else:
print var + " is a valid entry. Good job!"
You might be intersted in the pass or break statements too...pass is used to basically 'do nothing', so something like:if animal == "dog":
pass #aka don't do anything
else:
print "not a dog"
break is used to break out of a while or for loop, so something like:for x in (1,2,3,4,5):
if x > 4:
break #aka stop looping
else:
print x